Delphi R4 compressor installed

[Cusser]

I installed a new Delphi R4 compressor yesterday into my 1994 Suburban, 200K miles, relatively straightforward. The old compressor hadn't seized or made noise, but started leaking last fall. I had to run out to CarQuest for the rear accumulator O-ring, as the ones supplied with the new accumulator did not include the thicker, smaller-diameter one like the one that had been on my older accumulator (fits in a small grove on the fitting coming from the firewall. Typical GM engineering on that firewall fitting, hard to get to, and I see why some have had issues with that fitting's threads. Also typical GM was the three mounting bolts for the compressor itself, not enough clearance to pull them all the way out because they hit the pulley edge; luckily, GM or a former mechanic had ground a flat onto the rounded bolt built-in "washer" or flange so if one turned them to align, then removal was possible. Maybe a mechanic installed the passenger side bolt backwards, but I had to loosen the radiator shroud to get that passenger-side bolt out. The new compressor did not have the switch in the rear, so I had to dig out the O-ring pliers and swap that over from the old one; the compressor instructions said to use a new O-ring (but that was not supplied), so I figured that the O-ring that sealed the plug on the new compressor would've fine for those models, so should be fine for the swapped-in switch. Was I really supposed to go find a NEW O-ring for that, couldn't Delphi have included that if it was necessary.

Neither the old accumulator or the old compressor contained a drop of oil, puzzling. I added 8 oz. of PAG/150 containing UV dye, 2 oz. to the accumulator and 6 oz. to the compressor itself, then rotated the compressor a bunch of times once I got it bolted to the Suburban. I have a laboratory vacuum pump, and pulled vacuum 45 minutes, then observed that the system held pressure half hour. Then I added about 66 oz. R134a (dual-air system); pressures were about 30 on low and 200 psi on high, and vent temperature was 30F below ambient at idle (39F). I checked the fittings I had installed with bubble solution, and didn't see any leaks, so washed that off. So I think I'm good to go, if I don't experience any leakage....At least it was a nice afternoon here.

[j cAT]

Originally Posted by Cusser

I installed a new Delphi R4 compressor yesterday into my 1994 Suburban, 200K miles, relatively straightforward. The old compressor hadn't seized or made noise, but started leaking last fall. I had to run out to CarQuest for the rear accumulator O-ring, as the ones supplied with the new accumulator did not include the thicker, smaller-diameter one like the one that had been on my older accumulator (fits in a small grove on the fitting coming from the firewall. Typical GM engineering on that firewall fitting, hard to get to, and I see why some have had issues with that fitting's threads. Also typical GM was the three mounting bolts for the compressor itself, not enough clearance to pull them all the way out because they hit the pulley edge; luckily, GM or a former mechanic had ground a flat onto the rounded bolt built-in "washer" or flange so if one turned them to align, then removal was possible. Maybe a mechanic installed the passenger side bolt backwards, but I had to loosen the radiator shroud to get that passenger-side bolt out. The new compressor did not have the switch in the rear, so I had to dig out the O-ring pliers and swap that over from the old one; the compressor instructions said to use a new O-ring (but that was not supplied), so I figured that the O-ring that sealed the plug on the new compressor would've fine for those models, so should be fine for the swapped-in switch. Was I really supposed to go find a NEW O-ring for that, couldn't Delphi have included that if it was necessary.

Neither the old accumulator or the old compressor contained a drop of oil, puzzling. I added 8 oz. of PAG/150 containing UV dye, 2 oz. to the accumulator and 6 oz. to the compressor itself, then rotated the compressor a bunch of times once I got it bolted to the Suburban. I have a laboratory vacuum pump, and pulled vacuum 45 minutes, then observed that the system held pressure half hour. Then I added about 66 oz. R134a (dual-air system); pressures were about 30 on low and 200 psi on high, and vent temperature was 30F below ambient at idle (39F). I checked the fittings I had installed with bubble solution, and didn't see any leaks, so washed that off. So I think I'm good to go, if I don't experience any leakage....At least it was a nice afternoon here.

when the air temp gets up to 80 deg F recheck your pressures ....60deg f is cool to get a good reading...where you live better to be undercharged than over...

the procedure you followed sounds good ...any fitting disturbed needs new O rings ....lubing the O rings with the pag 150 is also required ...

[Cusser]

I lubed the O-rings with Nylog, the AC Internet forum guys like that, and also lube the threads of the metal fittings with it. http://www.ackits.com/c/Nylog/Nylog+...brication.html

They also say R-12 type mineral oil is better than PAG for lubing the O-rings, not sure why.

[j cAT]

Originally Posted by Cusser

I lubed the O-rings with Nylog, the AC Internet forum guys like that, and also lube the threads of the metal fittings with it. http://www.ackits.com/c/Nylog/Nylog+...brication.html

They also say R-12 type mineral oil is better than PAG for lubing the O-rings, not sure why.

if you have a r134 refrigerent system you use pag 150 oil on these O rings R12 oil is not compatible...

if you had R12 you would use the conversion oil which is compatile with the R12 oil but it is best to remove the old r12 oil first before conversion..

I don't understand why these a/c guys would tell you R12 oil on your R134 system O rings ...maybe be they want you to have problems ...